Energy efficiency ratings based on outdated climate data

Stephanie Stefanovic

Australia’s minimum energy standards for new buildings are currently based on decades-old climate data. The Nationwide House Energy Rating Scheme (NatHERS) is looking to evaluate this data ahead of a review of its requirements.

NatHERS currently requires buildings to be built at minimum to a 6-star (out of 10) energy rating. The issue however, is that its energy efficiency standards are based on climate data sourced from the Bureau of Meteorology from before 1986 to the end of 2005. This is problematic because nationwide mean temperatures have risen each decade since the 1940s, including at a rate of approximately 0.15 degrees per decade since the 1980s.

NatHERS is currently consulting on how to update its climate files ahead of a review (held every three years) in 2019. However, changes to the actual energy standards may not come into place until 2022 or later, according to the body. The standards have remained largely unchanged since 2010, barring some small changes in NSW last July.

According to Rob Sindel, managing director of CSR, most of Australia’s homes likely have an energy rating of just 1-star. This forces many Australians to rely heavily on heating and cooling, which leads to situations like the recent blackout in Victoria, which left more than 95,000 properties without power as temperatures reached up to 40°C in some parts of the state. Exorbitant energy bills are another common complaint from most Australians.

While there is a big focus on implementing renewable energy to curb high energy bills and carbon emissions, the International Energy Agency has noted that the gains from energy efficient buildings surpass those from renewables. However, reducing bills and emissions is not the only reason we should be improving the energy efficiency of our buildings.

“Australia is highly urbanised, and the quality of our buildings increasingly determines our quality of life and Australia’s attractiveness as a place to live and work,” according to a report from the Australian Sustainable Built Environment Council.

“Buildings that are well-designed and constructed for energy efficiency are also more comfortable, quieter, and tend to have better indoor air quality. These features also help boost resilience to the adverse effects of extreme weather.

“Research shows that patients recover faster and go home quicker in hospitals which are well-designed to save energy, students in highly efficient school buildings learn better and achieve better academic results, and office workers in high performing buildings think more clearly, are more productive and produce higher quality work.”